Try to use Shrinkwrap modifier on cloth, Snap mode - Outside, target - the mesh body, increase Offset a little to start seeing the effect.

Another useful technique, that's highly recommended by professionals, is to hide everything that's not rendered.

In the body mesh, add all points that's normally hidden by dress into a new vertex group. Then set up the mask modifier like this:

Note that mask modifier is disabled in viewport for baking cloth and enabled in render to hide parts of the mesh that's may intersect with cloth.

I advise you not to use sculpting for this task, even if it is possible it is time-consuming and should make jittering effect.

Try to use Shrinkwrap modifier on cloth, Snap mode - Outside, target - the mesh body, increase Offset a little to start seeing the effect.

Another useful technique, that's highly recommended by professionals, is to hide everything that's not rendered.

In the body mesh, add all points that's normally hidden by dress into a new vertex group. Then set up the mask modifier like this:

Note that mask modifier is disabled in viewport for baking cloth and enabled in render to hide parts of the mesh that's may intersect with cloth.